Conventionally, in navigation apparatuses, when a driver inputs a destination and sets search conditions, route search processing is carried out based on the search conditions, and based on map data, a route from an origin, which is indicated by the position of the guided vehicle, to a destination, is retrieved. In addition, the route that has been retrieved, that is, the retrieved route, is displayed along with the position of the guided vehicle on a map screen that is formed in a display unit, and guidance about the retrieved route, that is, route guidance, is carried out. Thereby, it is possible for the driver to drive the vehicle along the displayed retrieved route.
However, when passing through an intersection on the retrieved route, in the case in which the road that forms the retrieved route has a plurality of lanes, a lane list, which serves as a lane guide map, is displayed in a predetermined screen that is formed in the display unit (refer, for example, to Patent Document 1).
FIG. 1 is a drawing that shows an example of a display of a conventional lane list, and FIG. 2 is a drawing that shows an example of a display of a lane list that takes into account the connections between each of the lanes.
In this case, a section within a range that is a predetermined distance ahead of the position of the guided vehicle is set as a lane list display section, and a lane list Ls1 is formed for each of the intersections in the lane list display section that have a traffic signal. Reference numeral r1 denotes a road, Lk1 denotes the lane group that contains the road link from the position of the guided vehicle to the “Umedashinmichi” intersection, Lk2 denotes the lane group that contains the road link from the “Umedashinmichi” intersection to the “Oebashi Minamizume”, Lk3 denotes the lane group that contains the road link from the “Oebashi Minamizume” intersection to the “Yodoyabashi Kitazume” intersection, and Lk4 denotes the lane group that contains the road link from the “Yodoyabashi Kitazume” intersection to the “Yodoyabashi” intersection.
Lane group Lk1 includes lanes k1 to k5, lane group Lk2 includes lanes k11 to k18, lane group Lk3 includes lanes k21 to k28, and lane group Lk4 includes lanes k31 to k38, and in each of the lane groups Lk1 to Lk4, the lanes k2, k11, k21, and k31 are displayed as recommended lanes, in which travel is recommended, for each road link.
In addition, in the lane list Ls1, traffic sections that indicate the forward direction are determined for each of the lanes k1 to k5, k11 to k18, k21 to k28, and k31 to k38, and for each traffic section, arrows are appended that show the traffic direction, that is, the exit direction, at each of the intersections.
Specifically, the lanes k1 and k31 are left turn lanes, and arrows are appended that show that these lanes are left turn lanes. The lanes k2, k11, and k32 are left turn and through traffic lanes, and arrows are appended that show that these lanes are left turn and through traffic lanes. The lanes k3, k4, k12 to k16, k21 to k28, and k33 to k36 are through traffic lanes, and arrows are appended that show that these lanes are through traffic lanes. Lanes k5 and k37 are right turn and through traffic lanes, and arrows are appended that show that these lanes are right turn and through traffic lanes. Lanes k17, k18, and k38 are right turn lanes, and arrows placed showing that these lanes are right turn lanes.
In addition, because lanes k2, k11, k21, and k31 are recommended lanes, they are shown by making the color of the background that surrounds the arrows different so that they can be distinguished from the other lanes.
Therefore, on the retrieved route, in the case in which a left turn is made at the “Yodoyabashi” intersection after the vehicle has traveled forward along the road r1 up to the “Yodoyabashi” intersection, lane guidance is carried out so that the vehicle will pass through, in order, lanes k2, k11, k21, and k31. Note that the “Yodoyabashi” intersection is a retrieved route and a guided intersection at which guidance about the vehicle turning left, right, or travelling forward, is provided.
However, as shown in FIG. 2, in the actual road r1, because lane k2 and lane k14 are connected, lane k11 and lane k23 are connected, and lane k21 and lane k31 are connected, when the guided vehicle attempts to travel along lanes k2, k11, k21, and k31, which are the recommended lanes, the guided vehicle travels along lane k2 in the road link from the position of the guided vehicle to the “Umedashinmichi” intersection, enters lane k14 at the “Umedabashimichi” intersection, moves from lane k14 to lane k11 in the road link between the “Umedashinmichi” intersection and the “Oebashi Minamizume” intersection, enters lane k23 at the “Oebashi Minamizume” intersection, moves from lane k23 to k21 in the road link between the “Oebashi Minamizume” intersection and the “Yodoyabashi Kitazume” intersection, enters the lane k31 at the “Yodoyabashi Kitazume” intersection, travels along lane 31 in the road link between the “Yodoyabashi Kitazume” intersection and the “Yodoyabashi” intersection, and turns left at the “Yodoyabashi” intersection.
Thus, it is possible to consider displaying the lane list by taking into consideration the connections between each of the lanes between the lane groups Lk1 to Lk4 for each of the road links such that it is possible for the driver to recognize whether it is necessary move between lanes in each of the road links, and how the movement between lanes in each of the road links needs to be carried out, and such that, at each of the intersections such as those that are shown in FIG. 2, the road links at which an intersection is entered; that is, an entrance road, and a road at which an intersection is exited, that is, an exit road, are connected.    [Patent Document 1] Japanese Patent Application Publication No. JP-A-2005-214630